Sea level will rise by 0.9m in the next 80 years, millions of people will be displaced

Sea level is likely to rise more than 0.9m in the next 80 years. Most reefs in warm water areas will die. The oceans are warming at a rate twice as fast as they were in 1993.

These are just a few disturbing findings raised in a new report from the United Nations Intergovernmental Panel on Climate Change (IPCC).

The report, compiled by more than 100 authors from 36 countries, focuses on the state of the oceans and the ice rights (currently frozen parts) of the Earth. The findings in this report correct previous predictions of sea level rise: the authors assert that if the Earth's temperature rises by more than 3 degrees Celsius, the sea level will be higher than the average of 0, 9m in 2100.

The planet's average temperature has now increased by 1 degree C, and the global sea level has increased by about 15cm. But this pace of increase is getting faster and faster. By the end of the century, rising seas will cause 680 million people living in lowland coastal areas, along with 65 million people in small island states, to be affected or displaced.

The authors conclude that the main cause of sea level rise is the melting of the Antarctic and Greenland ice sheets.

"The biggest message to convey is that the number of people who will be threatened by rising sea levels in this century is very unusual," said Margaret Williams, managing director of the Arctic Program of the Wildlife Fund. gender, said. " The warming of the oceans and ice makes the situation twice as serious."

Sea level can rise by 0.9m

Even if the countries of the world achieved the goals set in the Paris climate agreement - keeping the planet from rising by more than 2 degrees Celsius - then according to the report, by the end of this century, the sea level would have remained will increase by 58cm.

The rise in sea level comes from two main causes : the melting of glaciers - glaciers and the rise of ocean temperatures (because water, like almost everything else, will expand when it is hot). up). But melting ice is the main reason among them.

The melting of the Thwaites glacier in the western Antarctic contributes to 4% of global sea level rise.

The ice in Greenland is melting six times faster than it was four decades ago - about 286 billion tons of ice each year.

Two decades ago, the average number was only 50 billion a year.

This defrost alone has contributed more than 1.2 centimeters to the sea level rise since 1972. Alarmingly, half of this sea level rise has occurred in the last 8 years.

Kulusuk town in the east of Greenland.

In Antarctica, meanwhile, the entire ice sheet is melting at a rate six times 40 years ago. In the 1980s, Antarctica lost 40 billion tons of ice each year. In the last decade, this number jumped to an average of 252 billion tons per year.

The ice loss rate of 5 glaciers in Antarctica has also doubled in the last 6 years.

Specifically, areas of the Thwaites glacier in the western Antarctic are losing 800m of ice each year, contributing 4% to global sea level rise. Thwaites are in danger of falling into an irreversible melting state, after which the glacier will lose all its ice over a 150-year period. This will trigger a chain reaction of melting, which can cause sea levels to rise by 2.4m compared to the 0.9m increase predicted by the IPCC.

Ice is melting on a cliff in Landsend, on the shores of Cape Denison in Antarctica, January 2, 2010.

In addition, the IPCC report shows that glaciers outside Antarctica and Greenland are also disappearing.

Smaller glaciers in the US, Europe, and the Andes are forecast to lose more than 80% of the existing ice and snow by 2100. That will " adversely affect leisure activities, tourism, and cultural heritages ".

" Many small glaciers in Washington, western United States, will disappear in the next few decades or within a decade at least," - Regine Hock, one of the authors said.

Coral reefs are in danger

The planet's oceans absorb 93% of the additional heat that greenhouse gases store in the atmosphere. Last year was a record-breaking hot year in the oceans - 2018 broke 2017's temperature record, and earlier 2017 broke a 2016 record. Scientists have never seen such heat. This is since they started measuring ocean temperatures in the 1950s.

According to the IPCC report, the ocean will absorb 2-4 times more heat in 2100 than the heat it absorbs between 1970 and 2018 - and that is if global warming is limited to 2 degrees C.

Heat waves at sea (defined as any day when the surface temperature of the sea exceeds the 99th percentile in that area) have doubled in frequency compared to 1982. If the Earth warmed up by 2 further degrees Celsius, these heat waves will occur 20 times the current frequency.

This is especially serious because warm water can cause corals to repel the algae that waves inside its tissues, then turn white and die. This phenomenon is called "coral bleaching". At the current rate, 60% of all reefs will be highly or seriously threatened by 2030, and 98% of all reefs will be exposed to potentially hazardous conditions. muscles destroy each year.

Compared to last year, more than half of Australia's major coral reefs have died from bleaching.

Australia's major coral reefs encountered the second largest bleaching in 2017.

Even if the most ambitious goal of the Paris agreement is accomplished and world temperatures do not rise above 1.5 degrees Celsius (likely very low), then almost all warm-water reefs are forecast. will be extinct on a large scale - the IPCC report concludes.

Dead marine life will affect food security

Coral reefs cover less than 1% of the ocean floor, but the consequences of coral bleaching are out of control, as a quarter of all fish spend part of their life cycle. to live in these reefs. This means that coral loss will lead to serious consequences for coastal communities that rely on the coral ecosystem to sustain their livelihoods, to earn income from fishing, and tourism.

Approximately 3 billion people worldwide rely on both caught and farmed seafood as a major source of protein. Catching fish in the reefs each year brings in US $ 6.8 billion worldwide.

" The increase in the risk of seafood food insecurity associated with the declining availability of seafood is expected to increase the risk to nutritional health in some seafood-dependent communities, like in the Arctic, West Africa, and small island developing countries. "

Catching salmon in Alaska.

Global warming can also cause food insecurity for Arctic residents, including indigenous people, because those changes will disrupt animal husbandry, hunting and fishing.

" There are short, fragile connections between the dramatic decline in fish stocks, starving seals, the disappearing whales, and the lives of Arctic peoples" - Becca Robbins Gisclair, director Arctic program at Conservation Ocean organization said.

" If we do not act, food security coupled with billions of people will be at risk, entire ecosystems will disappear, coastal communities and islands below water levels," she added. will be submerged by rising sea levels, and people will no longer have the same opportunity as before to find the wonders of nature of the ocean.

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